Bio 200 midterm 1
TEM - answer Transmission electro microscopy: cross section of the cells, able to
distinguish organelles, high magnification and resolution
REALLY EXPENSIVE and cells must be dead
Range of size : 200nm-.2nm
SEM - answer Scanning Electron microscopy: Image appears to be 3-D, high
magnification and resolution, great for seeing surfaces.
Fluorescent Microscopy – answer Fluorochromes emitted to stain certain cell parts. PIN
points structures
Do not see the rest of the cell, the light may be out of focus and the fluorochromes may
bind to the wrong organelle
Low magnification and resolution
Cannot see live cells
Bright field microscopy - answerBright background, see general cell structure, SEE
LIVING CELLS, inexpensive.
Greater than 200 nanometers can be seen
Cannot see majority of organelles, poor magnification and poor resolution
FRAP - answerFluorescence recovery after photobleaching
1. label phospholipids w/ chemical
2. bleach with a laser
3.monitor for FRAP--> unbleached proteins migrate into bleached area
Cholesterol (form) - answerLarge shape and assymetrical
Amphipathic
varies in its properties in hot and cold temps.
Cholesterol in high temps - answerRing structure of cholesterol stiffens cell membranes
Cholesterol in low temps - answerIncreases bilayer fluidity because it prevents tightly
packed fatty acids
Fluidity factors - answerdegree of unsaturated lipids
FattyAcid tail length (more fluid if short)
Cholesterol
TEM - answer Transmission electro microscopy: cross section of the cells, able to
distinguish organelles, high magnification and resolution
REALLY EXPENSIVE and cells must be dead
Range of size : 200nm-.2nm
SEM - answer Scanning Electron microscopy: Image appears to be 3-D, high
magnification and resolution, great for seeing surfaces.
Fluorescent Microscopy – answer Fluorochromes emitted to stain certain cell parts. PIN
points structures
Do not see the rest of the cell, the light may be out of focus and the fluorochromes may
bind to the wrong organelle
Low magnification and resolution
Cannot see live cells
Bright field microscopy - answerBright background, see general cell structure, SEE
LIVING CELLS, inexpensive.
Greater than 200 nanometers can be seen
Cannot see majority of organelles, poor magnification and poor resolution
FRAP - answerFluorescence recovery after photobleaching
1. label phospholipids w/ chemical
2. bleach with a laser
3.monitor for FRAP--> unbleached proteins migrate into bleached area
Cholesterol (form) - answerLarge shape and assymetrical
Amphipathic
varies in its properties in hot and cold temps.
Cholesterol in high temps - answerRing structure of cholesterol stiffens cell membranes
Cholesterol in low temps - answerIncreases bilayer fluidity because it prevents tightly
packed fatty acids
Fluidity factors - answerdegree of unsaturated lipids
FattyAcid tail length (more fluid if short)
Cholesterol
